This invention relates to a clamping apparatus for a tool component, such as a saw blade, suitable for use with a tool, such as a jigsaw or reciprocating saw. A second aspect of the present invention relates to an improved scrolling mechanism for a tool, such as a jigsaw or reciprocating saw.
It will be appreciated by persons skilled in the art that the first and second aspects of the present invention can be used together and/or independently of each other. In addition, whilst the following description refers almost exclusively to clamping apparatus and a scrolling mechanism for use with a jigsaw, it will be appreciated that both invention aspects can be used with any tool as required.
Tools, such as jigsaws, power saws or reciprocating saws, are typically provided with releasable blade clamping means for allowing saw blades to be replaced, removed and/or repaired as and when required. There are many different types of blade clamping means available and one example is disclosed in EP0587498 wherein a support is provided on a slideway which defines an engagement passage for a tail end of a saw blade. A retractable locking member is secured to the support and interacts directly with a protrusion portion on the saw blade. In order for a user to release the blade, they are required to move the retractable locking member. Since this release mechanism requires the user to directly come into contact with the blade, if the user accidentally slips during this maneuver they are likely to cut themselves on the blade, which is undesirable.
A further example of a blade clamping arrangement is disclosed in DE4313718. In this arrangement, two clamping jaws are provided which are radially movable relative to the longitudinal axis of a blade stroke shaft. In a clamped position jaws are pressed against opposite flat sides of the blade by a wedge mechanism. The wedge mechanism is formed by a screwcap having an inner conical surface. The outer surfaces of the clamping jaws are shaped so that movement of the screw cap with respect to the jaws moves the jaws between clamped and unclamped positions. Since the blade release mechanism is likely to require multiple rotations of the screw cap to move the same between said clamped and unclamped positions, this increases the time taken for a user to attach or release a blade. A problem associated with other blade clamping arrangements includes the requirement of special tools to enable the release and/or attachment of the blade to the tool.
A further known type of blade release mechanism includes a slidable sleeve member for movement of clamping jaws between clamped and unclamped positions. In this mechanism the clamping apparatus is connected to a shaft which is substantially square in cross section. A problem with this arrangement is that it cannot be easily used in combination with a scrolling mechanism or other mechanism wherein the orientation of the tool component held by the clamping apparatus needs to be moved via the shaft in use of the tool.